Method of vaporizing liquid fuels and means therefor



-R. IVI. PIERSON. METHUD 0F VAPORIZING LIQUID FUELS AND MEANS THEREFOR.

APPLICATION FILED SEPT.3, 1920.

LBSHQB.

Patented July 26, 1921.

'UNITED STATES i PATENT OFFICE.

ROBERT IVI. PIERSON, OF AKRON, OHIO.

METHOD OF VAPORIZING LIQUID FUELS AND MEANS THEREFOR.

Specification of Letters Patent. Patented July 26, 1921.

Application filed September 3, 1920. Serial No. 407,901.

nection with a carbureter or mixer of the suction-operated spray typez; and 1t relates especially to that class of vaporizers using hot products of combustion in a jacket or chamber in heating relation to the inlet pipe or passage,v as a medium for heating the mixture in said pipe or passage.

A common fault encountered in operating the ordinary exhaust-jacketed inlet pipe, or the ordinary hot-spot combination inlet and exhaust manifold, is that if the area exposed to hea-t is sufficient to vaporize the fuel at light loads when the throttle is nearly closed, the air in the mixture will become so overheated at open throttle as to be unduly expanded, and cause the motor to deliverless power than it should when heavily loaded. Furthermore, in using a manifold jacket supplied by a branch exhaust pipe and discharging into the atmosphere, the discharge is noisy at medium and heavy loads unless special provision is made to muffle it. These difficulties have led to the introduction of systems using a separate flame maintained by a special ignition apparatus, and fed by a small stream of lmixture which is either supplied by an auxiliary carbureter or is by-passed from the main carbureter, the products of combustion from this flame in some cases being led into the inlet manifold beyond the throttle valve. While such systems may afford improved heat regulation, they are lacking in maximum economy of fuel and require the maintenance of an additional stream of mixture in proper proportions for combustion, besides adding considerably to the complication and Cost of the apparatus.

The main objects of' my invention are to provide a simple and inexpensive, quietlyoperating vaporizer. which will afford ample heat for smooth running at nearlylosed throttle, and good acceleration when the throttle opening is increased under load;

which will avoid overheating of the mixture at heavy-load, and is preferably arranged to yield the advantages obtained by introducing a small quantity of cooled products of combustion into the mixture.

A further object'is to'improve the heat` transmitting properties of eXhaust-jacketed manifolds or inlet pipes, to provide a form of jacket which can be readily cleaned, and to facilitate making the connection between said jacket and the exhaust pipe.

My invention includes both a method and an apparatus.

In the accompanying drawings:

Figure 1 is a side elevation showing portions of an internal-combustion motor provided with a vaporizer constructed according to my invention, the cover of the heat-5 ing chamber or jacket being partly broken away and the retaining bolts omitted;

Fig. 2 is a section on the line 2-2 of Fig.v 1, without the carbureter and its attachments;

Fig. 3 is a section on the line 3-3 of Fig. 2;

Fig. 4 is a detail vertical section on a larger scale, taken through the lower retaining bolt and showing the regulating valve.

In the drawings, 10 is an ordinary explosion motor having exhaust ports or openings 11 in its cylinder block, and 12 is the motor exhaust pipe or manifold connected with said openings and held in place by means of the T-bolts 13, which also serve to retain the inlet pipe or manifold 14.- in connection with the inlet ports or openings 15. 16 is a small branch exhaust pipe having elbow fittings 17, 18 at the main exhaust manifold and at the jacket cover of the inlet manifold respectively, and a flexible section 19. 20 is a spray carbureter of familiar type, bolted to the inlet manifold and having a gasolenesupply connection 21, a float bowl 22, a jetcontrolling needle-valve 23, and a throttle valve 24 located in the passage leading from its mixing chamber to the manifold 14, at a point immediatelv anterior to its connection with the latter, this connection being horizontal in the present case, and the trunk of the manifold being inclined downwardly away from the motor. .Valve 24 controls the motors in the usual manner by varying the density of the combustible mixture without substantially varying its composition. The inlet manifold is of approximate T- form, with an uptake trunk portion 25 connected with the carbureter, and lateral branches 26 leading therefrom to the inlet ports 15 of the motor. 27 is a heating chamber or jacket which I prefer to extend only part way around those portions of the inlet manifold which it embraces, both for convenience in manufacture and also to facilitate the cleaning of said chamber. As here shown, this heating chamber includes the intersection of the trunk and branches of the manifold and a substantial portion of the trunk, and it extends about halfway around these portions at its deepest points, but it will be understood that considerable latitude of design is allowable in these particulars.

The chamber 27 is surrounded in the plane of the manifold by fixed walls 28 and is provided with fixed bottom or inner walls 29, 30, 31, all cast integrally with each other and with the trunk and branches of the manifold. The front or outer edge of the walls 28 is a fiat surface 32 against which rests a removable cover-plate 33 having the same side outline as the walls 28, and provided with a corresponding inner 'Hat edge face to form a closed joint therewith. This joint may be packed or may be machined and ground to a good fit. The cover is preferably somewhat dished in form and is held in place by two bolts 34, 35, which screw into threaded holes 36, 37 in -the body of the manifold. The manifold is also integrally formed with a series of baiies or members for increasing its heating surface, these members preferably, although not necessarily, taking the form of rib-like transverse bafiies 38, 39, 40, here shown as three in number, extending alternately from opposite sides of the heating chamber, part way across said chamber, and each consisting of a portion cast on the manifold body and a portion cast on the cover. The upper one 38 of these baffles includes the alined bosses in which the holes in the body and cover for receiving the bolt 34 are formed. The purpose of said baiies is to cause the exhaust^ gases to pursue a zig-zag path in passing from the inlet to the outlet of the heating chamber, and thus give up a greater portion of their heat to the walls of the chamber and therethrough to the exposed rear wall of the inlet pipe, thus rendering the semi-surrounding jacket 27 more effective for heating said pipe than itwould otherwise be. The portions of said baffles cast on the cover serve to stifen the cover and permit the number of retaining screws to be reduced. These baflles, however, are not absolutely essen-y tia It will be noted that the heating chamber 27 has its upper portion over the intersection between the trunk and branches of the manifold 14, and the fitting 18 of the branch exhaust pipe is screwed into a threaded hole in the cover 33 near the upper end of the chamber. At this intersection the sprayed fuel particles in the mixture abruptly change their direction and tend to strikethe horizontal top wall of the mixture passage, and as the exhaust gases supplied to the jacket have their highest temperature at this point, they are very eective in vaporizing the fuel. The intermediate and lower portions of the heating chamber .extend downwardly over a substantial part of the length of the trunk portion 25 of the manifold, and said chamber may terminate as near as desired to the inlet end of said manifold.

An important feature consists in leading the spent or partially cooled exhaust gases from the heating chamber 27- through a small fixed opening into the inlet pipe 14 at a point posterior to the throttle-valve 24, there to mingle withmthe air and fuel and pass on into the motor. Conveniently, this small opening and'a valve for controlling it may be located in or on the bolt 35, as shown in the drawings, although this location is not essential, nor is it essential that said opening shall be controlled by a valve. 41 is a longitudinal hole drilled in the inner end of the retaining bolt; 42 is a transverse passage in the boltleading to the passage 41 from the lowermost portion of the chamber 27; 43 is a needle-valve having a threaded stem which screws into the outer end of the bolt. said valve forming between itself and the outer end of the passage 41 the small fixed opening referred to,'whose size may be controlled by adjusting said valve; and 44 is a lock-nut on said stem, seated against the end'face of the bolt. By mounting the valve 43 upon the bolt 35, I am enabled to remove the cover 33 without disturbing the position of said valve with relation to its seat at the outer end of opening 41, and also to inspect or test the adjustment of the valve whilethe bolt is removed.

The opening into the inlet pipe past the valve 43 constitutes, as will be evident, an

'outlet from the heating chamber whose area is very small in comparison with that of the branch exhaust pipe 16 and with the flow capacity through said chamber, so that there will be a sufficiently rapid flow of heat into said chamber'by reason of the pressure of the exhaust gases and their contraction and condensation by cooling in said chamber effectively to vaporize the fuel, notwithstanding the smallness of the outlet. This restricted outlet, however, dams or chokes the flow of exhaust gases at open throttle to such an extent as to avoid overheating of the air in the mixture, also promoting a rapid cooling and silencing ofthe branch exhaust and tending to clear the discharge of soot by causing its separation and deposit in the'upper Iportions of the heating chamber. =Hence do not wholly limit myself to making this outlet lead into the inlet pipe nor to locating the heating chamber on that part of the mixture vpassage which is posterior to the carbureteror the throttle valve.

,In the operation of this apparatus, the hot products of combustion from the motor exhaust pipe 12, entering the heating chamber 'or jacket 27 of the inlet pipe 14 through the branch conduit 16, impart their heatv to all portions of the walls of said chamber and thus tend to gasify the unvaporized particles of fuel in the combustible mixture iiowing through said pipe. The resultant cooling of these exhaust gases renders them lit to be introduced into the combustible mixture through the opening .41, in such quantity as will not unduly dilute or raise the temperature of said mixture, this quantity being readily regulated by means of the valve 43, and this disposition of the discharge from the heating chamber effectivelv muiiles the noise of the discharged gases. The moisture and neutral gases in the cooled products of combustion present in the combustible mixture have a beneficial effect on the operation of the motor, by keeping down the maximum temperatures of compression and explosion, and reducing the detonations called knocking and pinking. -These eii'ects are also diminished, the tendency toward formation of carbon .in the cylinders is reduced, dilution ofthe crank-case oil is largely overcome, the motor warms up more quickly after standing,

`acceleration and fuel economy are improved, and the liability of the motor to stall at low speed is reduced by reason of the better vaporization of the fuel incident to heating the inlet pipe with a high-temperature medium. Overheating of the mixture is prevented not only'because of the restricted outlet past the valve 43 as above mentioned, but also by reason of the fact that the exhaust gases are diverted into the chamber 27 in proportion to the strength of the suction in the inlet pipe 14, the rate of flow through the passage 41 varying directly as said suction and hence varying inversely as the rate of flow of the combustible mixture past the throttle valve 24 and through the inlet pipe, especially at light load; this suction, and consequently 'the draft of gases through the chamber, being greatest when the throttle Valve is most nearly closed and when the necessity of heating is greatest because of slow movement of the combustible mixture .and relatively low temperature of the exhaust, the draft diminishing as the pressure of the mixture builds up in the inlet pipe and the pressure and temperature'of the exhaust increasing when the throttle is opened.

lstruction, more economical of fuel, and less liable to derangement than those using a separate heating flame, and the supply of heat is also more uniform over the entire range of: operation, since the higher temperature and pressure of the motor exhaust under medium and heavy loads are automatically availed of to supply heat to the greater flow of combustible mixture under these conditions, and thus partially to compensate for the increased pressure in the inlet pipe and the consequent decreased draft through the jacket at open thottle.

Aside from or in addition to the foregoing advantages, the special construction of inlet manifold with heating chamber and cover as shown and described, allows for direct or straight access to all parts of said chamber, for the purpose of removing accumulations of soot and oil from the exhaust, which would gradually reduce the heat-transmitting efiiciency. rlhe chamber 27 contains no inaccessible pockets or passages, and hence can quickly and easily be wiped free of these accumulations when the cover 33 is removed. A

When installing the device, the exhaust manifold and the body lof the inlet manifold being mounted, the elbow fittings 17, 18 screwed in place and one end of the iiexible pipe section 19 slipped into one of said ittings, the connection of the branch exhaust pipe 16 with the cover 33 is preferably then completed While said cover is detached, by telescoping the other end of said flexible section 19 into the corresponding elbow fitting, after which the cover may readily be screwed' in place by means of the Y attaching bolts 34, 35, which screw into the body of theinlet manifold.

It will be understood that my invention may be applied in various ways to differing styles of inlet manifolds, and is not wholly limited to the details of construction herein described. u

Having thus described my invention, what I claim is 1. The method of operating internal-combustion motors which comprises mixing thev air and fuel sprayin a suction carbureter,

&

wall of the mixture passage in a region posterior to the throttling point, thereby heating the fuel in said passage and cooling the gases, and discharging the cooled gases into said passage at a point posterior to the throttling point.

3. Internal-combustion motor apparatus comprising, in combination with the motor, a main motor exhaust pipe, means for supplying a mixture of ,air and sprayed fuel to the motor, means for varying the density of said mixture Without substantially varying its composition, a mixture supply pipe having a heating chamber in branch connection with said exhaust pipe, and an outlet from said chamber into said pipe.

4. Internal-combustion motor apparatus, comprising in combination with the motor, a motor exhaust pipe, a carbureter, means for varying the density of the mixture from said carbureter Without substantially varying its composition, a mixture inlet pipe leading from the carbureter to the motor, a chamber in heating relation withsaid inlet pipe, a branch connection from the exhaust pipe entering said chamber at a point relatively near the motor, and an outlet from said chamber into the inlet pipe at a point relatively remote from the motor.

5. Internal-combustion motor apparatus comprising, in combination with the motor, a main motor exhaust pipe, a carbureterhaving a posterior throttle valve, an inlet pipe connecting said carbureter With the motor and having a chamber in heating relation therewith, a branch conduit connecting said chamber with the exhaust pipe, an outlet leading from said chamber into the inlet pipe on the motor side of the throttle valve, and a valve in said outlet controlling the volume ofproducts of combustion passing4 through said branch conduit and heating chamber into the inlet pipe.

6. A combustible-mixture inlet pipe for internal combustion motors having a chamber located in heating relation therewith and provided with an inlet for exhaust gases and an outlet therefor into said pipe, said chamber having means for causing the exhaust gases to take a zig-zag course in passing therethrough to said outlet.

.7. A combustible-mixture inlet pipe for internal-combustion motors having a carbureter connection at one end and a motor connection at its opposite end, a heating chamberl on said pipe provided with a removable closure, a motor-exhaust inlet to said chamber at a point relatively near the motor-connection end of said pipe, and an outlet from said chamber into said pipe at a point relatively near the carbureter connection end thereof.

8. A combustible-mixture inlet pipe for internal combustion motors having a heating:

chamber formed thereon and extending part Way around the pipe on the' side away from the motor, a cover for said chamber, Whose thereof to straight access from one side of the pipe, and means for admitting exhaust gases to and discharging them from said chamber.

10. A combustible-mixture inlet manifold for internal combustion motors, of approximate F-form, integrally formed With the fixed Walls of a heating chamber embracing the trunk and the intersection of the trunk and branches of the manifold, and open on the side of the manifold opposite to the outlets of said branches, a removable cover for the open side of said chamber,an exhaust-gas inlet to said chamber substantially over said intersection, and an outlet from said chamber into said trunk.

11. A combustible-mixture inlet pipe for internallcombustion motors having a heating chamber with fixed Walls and portions of gas bafles formed integrally With 'the Walls of the manifold, a removable cover for said chamber having other portions of Said baffles integrally formed thereon, an exhaust gas inlet to said chamber, and an l{exhaust-gas outlet leading from said cham- 12. A combustible-mixture inlet manifold for internal combustion motors, of approximate T-form, having a chamber in heating relation thereto embracing the trunk and the intersection of said trunk with the branches of the manifold, the inlet end of said chamber being substantially over said intersection and the outlet end over said trunk, a removable cover for said chamber permitting free access to its interior for cleaning the chamber and having an exhaustgas inlet at said inlet end, and an exhaustgas outlet leading from said outlet end into the trunk of the manifold.

13. A combustible-mixture inlet manifold for internal combustion motors having a chamber in heating relation thereto, a removable cover for said chamber, an exhaustgas inlet to said chamber, a retaining bolt for said cover formed with an outlet from the chamber into the manifold, and a valve on the bolt controlling said outlet.

14:'. lnternal combustion motor apparatus,

comprising, in combination with the motor, a motor exhaust pipe, an 'inlet pipe formed with a heating chamber closed on its inner side and open on the side away from said motor, a cover for said chamber removably secured in place by means of attaching de vices connected with the body of said inlet pipe, and a branch pipe connecting said ex haust pipe with said chamber and including a section mounted on said cover and another section telescoping with the rst-said section.

Y 15. Internal-combustion motor apparatus comprising, in combination with the'motor, a motor exhaust pipe, a carbureter having a throttle-valve posterior to its mixing chamber, a mixture inlet passage leading from said carbureter rto the motor and provided with a heating chamber, in branch connectio with said exhaust pipefand a fixed cho e outlet from said chamber into the interior of the inlet pipe.

16. Internal-combustion motor apparatus comprising, in combination with the motor, a main motor exhaust pipe, a carbureter having a throttle-valve, a mixture pipe connecting said carbureter with the motor and having a heating chamber in -branch connection with-the exhaust pipe, and an outlet leading from said chamber into the mixture pipe on the posterior sidevof the throttle valve.

17. Internal combustion motor apparatus,

comprising, in combination with the motor,

a main motor exhaust pipe, a carbureter havin a'throttle-valve, an inlet pipe connecting said carbureter with the motor, a heating jacket on said inlet pipe, a branch passage connecting lthe exhaustffi with one end of said jacket, anda cooked)e gas outlet leading from the opposite end of said jacket into the inlet pipe on the posterior side of said throttle valve.

18. Internal-combustion motor apparatus comprising, in combination with the motor, a main motor exhaust pipe, a carbureter, a mixture inlet pipe leading upwardly therefrom to the motor and provided with a heatportion located over the intersection of said trunk and branches and another portion located lower down on the trunk, and an outlet from the latter portion through the' wall of said jacket into the interior of. the trunk.

20: A combustible-mixture inlet manifold for internal-combustion motors having a trunk and lateral branches at the upper end of said trunk, a heating jacket provided with a hot-gasinlet and having portions located over said trunk and over its inter- Section with said branches, a fixed outlet from lthel lower portion of said jack restricted with reference to said inlet, and a baffle structure located in said chamber between said inlet and outlet. Y

21. A combustible-mixture inlet pipe for internal-combustion motors having a substantially upright portion, a chamber located in heating relation to said portion and provided with an inlet for hot gases at its upper end, an outlet from the lower end of said chamber into the interior of said inlet ipe, and a baffle structure located in said c amber between its' inlet and outlet.

In testimony whereof I have signed my 'name to this specification.

ROBERT M. PiERsoN. 'i 

